Fairly large piece of learner's embroidery without edges (5)
I believe the answer is:
ample
'fairly large' is the definition.
(I've seen this before)
'piece of learner's embroidery without edges' is the wordplay.
'piece of learner's embroidery' becomes 'sampler' (a sampler helps someone learn to embroider).
'without edges' means to look at the middle letters.
The centre of 'sampler' is 'AMPLE'.
(Other definitions for ample that I've seen before include "Plentiful, quite enough" , "Fully enough" , "Fairly large" , "Buxom" , "Large, accommodating" .)